Blow-off valve for pneumatic tires



June 26, 1923. 1,459,939

- A. H URTUBEES BLOW-OFF VALVE FOR PNEUMATIC TIRES Filed April 10, 1922 5 A H. UHTU BEES Patented June 26, 1923.

ALFRED 3. cameras, or MINNEAPOLIS, MINNESOTA.

BLOW-OFF VALVE FOR PNEUMATIC Application filed April 10, 1922. Serial No. 551,867.

To all whom it may concern:

Be it known that I, ALFRED H. Un'ro'enns, a citizen of the United States, residing at Minneapolis, in the county of Hennepin and State of Minnesota, have invented certain new and useful Improvements in Blow-Oil Valves for Pneumatic Tires, of which the following is a specification.

This invention has reference to devices for preventing excessive air pressure in pneumatic tires, and the main object is to provide an efficient and practical valveconstruction, which, when set at a predetermined pressure limit, will allow air to escape. from the tire when a desired pressure is exceeded. The pressure of the air in a tire is often dangerously increased when the same is being inflated, and also when the car is driven over a hot road or pavement where the heat causes the air inthe tire toexpand and proportionately increase I often in blow in pressure, resulting very outs, especially-where the casing of the tire is worn to a considerable extent.

A further object is to provide means in combination with such a valve structure for regulating the blow ofl pressure, point of the same, so vthat air will be allowed to escape only when a predetermined pressure is exceeded. Further objects will be dis closed in the course of the following specification, specifically pointed out in the claim appended hereto, and clearly illustrated in the accompanying drawing, m.

which:

Fig. 1 is a detail fractional portion of a vehicle wheel, showing my invention thereto.

Fig. 2 is an enlarged detail diametrical section through the valve embodying, my invention, asseen substantially 'on the line 2-2 in Fig. 1.

Fig. 3 is an elevation of a regulating tool which may be conveniently used in adjusting the valve.

Fig. 4 is an enlarged detail view of the lock nut 21.

Figs. 5 and 6 are enlarged detail views of the adjusting nut or plug 19.

Referrin to the drawing by reference characters, designates the spoke of a wheel havin a felly 8 and a pneumatic tire 9 therea out, 10 indicating the usual valve through which the tire is inflated.

My improved safety valve consists of a main body member 11, which is tightly .se-

slot 23in its upper face,-

the application of cured to the tire tube 12, as at 13, in any convenient manner. The outer side of the bod member 11 'isthreaded to receive a per orated cap 14, and a nut 15 which clamps down onto the felly 8.

Within the body member 11, which is substantially. hollow, is provided, near the lower'end thereof, a valve seat 16, seating a ball 17. The ball 17 is held firmly in its seat by a spring 18, the upper end of which enga es against an adjusting nut or plug 19 w ich screws in threads 20- on the inside of the body member 11. A lock nut 21 screws down on the adjusting nut 19 and serves to lock it in the position desired. The nut 19 is preferably formed with a central air escape port 22 and a transverse while the nut 21 has -a wide slot '24 running diametrically thereacross. v

An ordinary screw driver may be used to adjust this valve, but. it is found preferable to use an adjustingftool similar to the one shown in Fig. 3. This tool consists of a'shank 25 having a screw-dr'iver point 26 .and a suitable handle 27. The shank may he graduated, as shown, so that a predetermined pressure desired is indicated when such indicating mark is even with the top of the body member .11, it being understood that the point 26.0f the adjusting tool is seated in the slot 23 at such time.

When adjusting the pressure of the valve the cap 14 is first removed. It may also be found desirable to remove the lock nut 21,

but this is not necessary. By turning said nut 21 one 'or two revolutions up it will allow the plug 19 tobe rotated, and the slot 24 will allow the point 26 of the adjusting tool to drop. down into the seat 23, at which time both members 19 and 21 may be turned simultaneously. Now if a pressure of no more than eighty pounds-is desired in the tire the adjusting tool is turnedv down until the indicating character 80 is even with the top of the valvebody 11. Then the tool is lifted up until it engages the slot 24 only. The nut 21 is then turned down tightly to lock the plug 19, when the tool is removed and the cap 14 replaced.

When an air supply tube is to thevalve 10,-or when by reason of heated pavement the pressure in the tire increases to more than eighty pounds, then said air, which communicates with the valve seat 16 28, raises the ball .17 against through a duct now applied the pressure of the spring 18 until the pressure on each, side of' the ball is equal, or eighty pounds per square inch, when the escape will cease.

It is understood that suitable modifications may be made in the construction of this invention, provided, however, such:

modifications come withinv the spirit and scope of the appended claim. Having now therefore fully shown and described my invention 'what I claim 'to be new and desire toiprotect by Letters Patent is:

valve of the character described havmember having a transverse groove in its 20 upperface and said locking member havinga transverse slot through which a tool may be dropped to engage said channel.

In testimony whereof I afiix my signature. a

ALFRED H. URTUBEES. 

